DebugInfo: Emit only declarations (not whole definitions) of non-unit user defined types into type units

While this doesn't come up in reasonable cases currently (the only user
defined types not in type units are ones without linkage - which makes
for near-ODR violations, because it'd be a type with linkage referencing
a type without linkage - such a type can't be validly defined in more
than one TU, so arguably it shouldn't be in a type unit to begin with -
but it's a convenient way to demonstrate an issue that will become more
revalent with homed modular debug info type definitions - which also
don't need to be in type units but more legitimately so).

Precursor to the Clang change to de-type-unit (by omitting the
'identifier') types homed due to strong linkage vtables. (making that
change without this one would lead to major type duplication in type
units)

llvm-svn: 359122

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 816dd5b66e1..e31b1e5c3ad 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2749,6 +2749,22 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
   CU.addDIETypeSignature(RefDie, Signature);
 }
 
+DwarfDebug::NonTypeUnitContext::NonTypeUnitContext(DwarfDebug *DD)
+    : DD(DD),
+      TypeUnitsUnderConstruction(std::move(DD->TypeUnitsUnderConstruction)) {
+  DD->TypeUnitsUnderConstruction.clear();
+  assert(TypeUnitsUnderConstruction.empty() || !DD->AddrPool.hasBeenUsed());
+}
+
+DwarfDebug::NonTypeUnitContext::~NonTypeUnitContext() {
+  DD->TypeUnitsUnderConstruction = std::move(TypeUnitsUnderConstruction);
+  DD->AddrPool.resetUsedFlag();
+}
+
+DwarfDebug::NonTypeUnitContext DwarfDebug::enterNonTypeUnitContext() {
+  return NonTypeUnitContext(this);
+}
+
 // Add the Name along with its companion DIE to the appropriate accelerator
 // table (for AccelTableKind::Dwarf it's always AccelDebugNames, for
 // AccelTableKind::Apple, we use the table we got as an argument). If